In the manufacture or assembly of a vehicle body, it is known to have a body assembly line including a plurality of stations in which the vehicle body is assembled and forwarded as the assembly work proceeds. Typically, the major components of the vehicle body are formed of low carbon steel or steel-based alloy panels that are welded together in the general welder (i.e., a station wherein primary welding operations are performed to connect the vehicle body components to create the body-in-white body).
The substitution of aluminum or aluminum-based alloy roof panels for the low-carbon steel or steel alloy roof panels most commonly used in motor vehicles is an attractive option for vehicle mass reduction. Often, however, the remainder of the vehicle body structure continues to be fabricated of steel. Joining an aluminum roof panel to a steel body panel presents difficulties because the aluminum roof component cannot be set and joined in the existing general welder due to equipment and process constraints. Therefore, it is known for manufacturers to secure the aluminum roof panel to the steel body panel after the weld process in assembly. This process typically includes an adhesive bonding operation and fasteners can also be used to secure the aluminum roof panel to the steel body panel. However, existing vehicle body assembly lines are not adapted for assembly of both steel roof panels and aluminum roof panels to the vehicle body.